Ear protector



Oct. 4, 1955 H. E. VON GIERKE 3 EAR PROTECTOR Filed May 25, 1954 IN VEN TOR.

#f/V/W/V [064,9 rand/[66f BY w, n p- W/ ///.6 irmcwiy United States Patent EAR PROTECTOR Henning E. Von Gierke, Medway, Ohio, assignor to the United States of America as represented by the Secretary of the Air Force Application May 25, 1954, Serial No. 432,339

6 Claims. (Cl. 128-152) (Granted under Title 35, U. S. Code (1952), sec. 266) This invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

This invention is directed to an improved earplug so constructed as to increase protection for the human ear and particularly at low frequencies of sound. This problem has become particularly pronounced with the development of propeller and jet noises.

Conventional methods of ear protection try only to attenuate sound physically before it reaches the eardrum. This present invention applies in combination this principle and the fact that a static pressure difference between both sides of the eardrum makes the ear itself less sensitive to sound to the fabrication of a novel improved earplug unit whereby to provide a distinct advance in the art.

The conventional earplugs attempt merely to close the auditory canal against incoming sound with plastic, cotton or other such material in a generally moulded form which has an effect to diminish sound level at the eardrum by attenuation of sound physically, which protection varies in accordance with the material and shape given the material employed.

The invention described herein goes beyond this prior art to provide in the practical embodiment of the invention shown herein a novel earplug structure which enables the application of negative as well as positive pressure in the auditory canal relative to the atmospheric pressure. The employment of this novel structure in the earplug provides a marked reduction in the sensitivity of the ear and this reduction of sensitivity is even more marked at increased sound levels.

The advantages of the novel earplug will be readily obvious to those versed in the art from the following description thereof taken in conjunction with the accompanying drawings wherein:

Fig. 1 is a perspective view showing the method of application of the novel earplug.

Fig. 2 is a perspective view of the novel earplug.

Fig. 3 is a cross-section of the improved novel earplug;

Fig. 4 is a modification of the invention shown in Fig. 3 of the drawings.

The earplug in its preferred form shown in Fig. 1 of the drawing is designated generally by the numeral 1 and has an ear piece 2 shaped for the most convenient fit to the outer ear and for insertion in the auditory canal. The ear piece 2 has a recess 3 in the outer end as well as a recess 3 in the inner end. Axially of the earpiece 2 is a small channel or passage 4 opening into the respective recesses 3 and 3 at the respective ends thereof. A deformable balloon element 5 having an open end is secured and sealed by its open end to the earpiece 2 in the inner recess 3' thereof by any suitable means, depending on the material employed, which material should be deformable but stiff enough so that upon application of pressure it will deform and then on release of the balloon, it will expand with sufiicient spring-like 2,719,523 Patented Oct. 4, 1955 2 force to its original shape. As can be seen from the drawings, the passage or channel 4 provides an opening from the auditory canal to the hollow chamber in the bulb or balloon 5 in use. The balloon portion is intended to enclose an air volume of from 0.2 to 1 cc. of air.

In employing the novel earplug, before insertion thereof into the auditory canal, the balloon portion 5 is compressed between the thumb and forefinger as seen in Fig. 1. Then the earpiece 2 is inserted far enough into the auditory canal to provide an effective seal of the car while retaining the balloon portion compressed be tween the fingers. As an air-tight seal is made with the earpiece in the auditory canal, the fingers are released from the balloon. The balloon as it expands draws in air from the inclosed ear canal through channel or passage 4. In this way the pressure immediately on the eardrum is substantially reduced as is obvious and accordingly the ear sensitivity is reduced as the static pres- Sure differential between opposite sides of the eardrum is increased. It is noted that whether the increase in static pressure differential is positive or negative the ear sensitivity is decreased and will be reduced uniformly up to a frequency of 1000 C. P. S. Thus the improved earplug gets good sound attenuation and provides comfort from the earpiece while providing a means to insure a static pressure differential on the eardrum which substantially reduces the ear sensitivity, giving greatly increased protection.

T he channel 4 may be defined by a lining of hard tubing if so desired.

The novel earplug employing in its preferred form the principle of negative pressure on the eardrum appears to have more advantages than the modified form of Fig. 4 which employs the positive principle since it is a simple device, it is easier to use and provides a more ready seal. However, the invention can be easily modified as shown in Fig. 4 of the drawings to employ the positive pressure principle by employing in addition a clamp on the earplug so that on insertion of the earpiece in the auditory canal the balloon is in its expanded condition and upon an airtight seal being made therein the clamp is closed to positively compress the balloon to apply a positive pressure differential on the eardrum which similarly reduces the sensitivity thereof.

One method of providing a positive pressure differential as shown in Fig. 4 employs a finger plate 6 seated in a flanged recess in balloon member 5. In the recess beheath the plate is seated the outer end of a rod 7 having its other end slidably mounted in a recess 8 in earpiece 2. The rod 7 is reduced in diameter at spaced locations 9 for cooperation with spherical lock elements 10 seated in an annular recess in earpiece 2. Upon insertion of the earpiece 2 the balloon 5 is left in expanded condition in this modification till an effective airtight seal is obtained in the auditory canal. Then the finger plate 6 is pressed to move the rod 7 a predetermined amount so that a lock is effected by the lock elements 10 engaging a recess in the rod 7 to retain the balloon in compressed condition in a manner as is obvious from Fig. 4 of the drawings.

One of the particular advantages of the improved earplug is the greater reduction of loudness of sound frequencies in the audible range up to 1000 C. P. S. This is particularly important since in this low frequency range the sound attenuation by available earplugs is not very good. This is particularly important where propeller and jet noise hazard is concerned as providing a protection thereagainst which is not available in the earplugs now available.

As can be readily seen the present invention provides a protection not provided nor contemplated in the prior art. Whereas specific embodiments of the invention have been shown, many modifications and applications thereof will be readily apparent therefrom to those versed in the art and such is considered within the scope of the invention.

I claim:

1. An earplug comprising a substantially cylindrical earpiece for insertion in the auditory canal to establish an air-tight seal therewith, compressible means connected to said earpiece and extending outwardly thereof to define a hollow chamber, and means in said earpiece defining a passage to the auditory canal from said chamber whereby on insertion of the earpiece in the auditory canal while maintaining compression on said compressible means and release thereof upon the earpiece effecting an air-tight seal in the auditory canal, air will be drawn into said chamber to decrease the pressure on the eardrum and reduce the sensitivity of the ear.

2. An earplug comprising an earpiece for insertion in the auditory canal to establish an air-tight seal therewith, resilient bulb means having one open end, said open end being sealed to one end of said earpiece, a passageway in said earpiece connecting the said bulb means and the auditory canal whereby on compression of said bulb means during insertion of the earpiece and release there of upon proper positioning of the earpiece, air will be drawn into the bulb to decrease the pressure in the auditory canal and reduce the sensitivity of the ear.

3. An earplug comprising means to seat in the auditory canal and provide an air-tight seal therewith, a passageway through said seating means to open into the auditory canal and means connected to said seating means and in communication with said passageway operable to produce a static pressure dilferential on the eardrum whereby to reduce the sensitivity of the ear.

4. An earplug comprising an earpiece for insertion in the auditory canal to provide an airtight seal therewith, a passageway through said earpiece to open into the auditory canal at one end and hollow deformable means arranged to normally define a predetermined shape sealed to the end of the earpiece and communicating with the passageway operable to produce a static pressure differential on the eardrum whereby to reduce the sensitivity of the ear.

5. An earplug comprising an earpiece for insertion in the auditory canal to provide an air-tight seal therewith, means defining a passageway through said earpiece, a hollow resilient bulb connected to said earpiece at said outer end and open to said pasasgeway, and means to control the bulb whereby on insertion of said earpiece in the auditory canal and operation of said control means, a static pressure dilferential will be efiected on the eardrum thereby reducing the sensitivity of the ear.

6. Apparatus for reducing the sensitivity of the ear comprising adapter means for seating in predetermined relation to the ear, enclosed compressible means in secured association with said adapter means and operatively connected to said auditory canal, said compressible means being operable to introduce a static pressure differential on the eardrum whereby to reduce the sensitivity of the ear.

References Cited in the file of this patent UNITED STATES PATENTS 2,476,589 Driskill July 19, 1949 FOREIGN PATENTS 225,607. Germany Mar. 8, 1910 

